1. Field of the Invention
The present invention relates to an eyeglass frame, an eyeglass, and a method of manufacturing an eyeglass frame. More specifically the invention relates to an eyeglass frame comprising a pair of temple bars pivotally connected with a frame front of the eyeglass frame. In particular the invention relates to eyeglass frames comprising hinge means fitted with friction members.
As used herein the term eyeglass relates to the well known accessory which substantially comprises two lenses of glass or of other refractive or tinted, transparent material intended to be worn in front of the eyes of the user enabling him to obtain a corrected or a darkened view through the glasses, and a form of spectacle frame arranged to keep the lenses or glasses expediently fixed in the preferred position of use, where the user can look straight forward with both eyes and with parallel lines of sight through the respective lenses.
It is well known to provide such eyeglass frames with a frame front for holding the glasses and with a pair of temple bars for supporting the frame, which temple bars are connected to the frame front by means of hinges so as to allow the eyeglass to be folded up when not in use.
Even though a variety of eyeglasses are available, development is still taking place in order to find new solutions which might gain market shares, e.g. by offering particular features or cost benefits or through offering new aesthetic features.
2. Description of the Prior Art
U.S. Pat. No. 5,325,132 describes an eyeglass frame comprising a hinge with an eyelet on the temple bar for insertion between a pair of eyelets on the frame front and for fixation with a hinge pivot. The patent teaches a solution comprising a coil spring for axial biasing of the hinge in connection with the hinge pivot in order to ensure a firm hold of the temple bar. The hinge part is relatively bulky and implies a relatively delicate shaping and assembly of several different components.
U.S. Pat. No. 4,084,889 shows an eyeglass frame wherein a pair of coaxial hinge pivots on each one of the temple bars engage in respective openings in eyelets on the frame front of the eyeglass frame, and wherein a respective blade spring imparts a transverse bias force onto the hinge pivots of each one of the temple bars. The purpose of this bias force is to counteract spurious movements of the temple bar when in other positions than fully opened. A solution of this kind is considered complicated to manufacture and to assemble. With this solution the hinge pivots are subjected to loading and local wear in one side. The friction retention of the temple bar by means of the blade spring will hardly be able to completely avoid noticeable play. This play will likely vary dependent on the manufacturing tolerances and wear.